HPV: life cycle and replication strategy Flashcards
where can PVs mostly be found
in vertebrate species
what is the structure of the PV genome
circular 8kb double strand
what are the 2 main type of classification of PVs
alpha and beta
regarding HPV genome organisation what are early and late ORFs
early expressed in non productively infected cells and late are expressed in productively infected cells
which HPV proteins are involved in the genome maintenance
E1,E2
which proteins are involved in genome maintenance and cell proliferation
E1,E2,E5,E6,E7
which protein are involved in genome amplification
E1,E2,E4,E6,E7
which proteins are involved in virus assembly
L1,L2
go over culture methods for HPV
where does disassembly of the capsid take place
endosome
what does L2 do when HPV enters the cell
genome trafficked to cytoplasm goes to nucleus to ND10 bodies
enhances this trafficking process
what does the early promoter do
P97 in undifferentiated cells directs expression of E6 and 7
where are late promoters
in differentiated cells drives expression of E4,L1,L2,E1
what role does LCR play
initial expression
virus latency
enhancer elements
binding site for E2
what do E2 proteins contain
DNA and dimerisation domain
transactivating domain in amino terminus
what do E2 proteins regulate
viral transcription
viral DNA replication
long term episome maintenance
what does truncated E2 do
can act as a repressor for transcritpion
what does PV replication require
DNA ori
E1
E2
does E2 stabilise the E1-ori interaction
yes
what else does E1 interact with
DNA pol
histone H1
cyclin E
Ubc9
what does the efficient cell cycle of PV depend on
association of E1 and S-phase specific cyclin E complex
what does increased poliferation of the superbasal cells allow
drive into s-phase and DNA replication in the stratified epithelium in prolonged G2 phase
what measures DNA replication
BrdU staining
what measures the cell cycle
cyclin expression
what is vegetative replication
essential for genome packaging
happens in terminally differentiated epithelia
oncoproteins are key for amplification in this stage
describe virus assembly and release
late gene products accumulate
L2 goes to nucleus
associate with PML bodies
L1 association as capsomeres
go to nucleus
interact with L2 and PML
encapsidation occurs
E4 protein needed for escape
